Filter bodies of filters, in particular of very large, industrially used filter systems, have to be cleaned at specific intervals in order to preserve their filtering function. Also, the removal of the filtered-out substances from the surface of the filter body or bodies reduces an inevitable drop in pressure occurring on the filter body during operation and thus maintains the function and lowers the operating costs.
In known filters comprising textile filter bodies in the form of textile tubes, this is carried out by a compressed air pulse which passes through the textile tubes and thus loosens filtered material which has accumulated on the outer wall of these textile tubes. The loosened filtered material can then be removed quickly using little energy.
However, as the system size of filters increases, so too does the nominal width of a valve from which pressure pulses are released. The increase in the nominal width of this valve is at the same time almost inevitably accompanied by an increase in the inertia of the valve during the opening process, thus slowing down the rise in pressure at the leading edge of the pressure pulse released thereby and reducing the cleaning effect thereof.
The invention is therefore based on the object of generating particularly effective pressure pulses which reliably ensure detachment of the filtered material and thus the operational reliability of the filter.